A cleaning site for road and rail car tankers emits a waste water stream of 200-250 m 3 /d. The waste water was originally treated in a physico-chemical waste water treatment plant. It was required to improve the effluent quality in order to meet the future discharge limits. As a possible treatment technique the sequencing batch reactor (SBR) technology, with an option for powdered activated carbon (PAC) dosing, was selected.Waste water originating from road and rail car cleaning installations is known to be potentially toxic/inhibitory. As a first step in the design procedure a pilot test was run for a period of 8 months. This pilot showed the SBR to be an appropriate technology for the treatment of the waste water. The PAC option was not feasible.Based on the pilot results a full scale installation, comprising a batch reactor with a diameter of 10.4 m and a maximum water depth of 17.3 m, was designed and successfully started up. This paper presents the highlights of the total project.